Date exclusion in a BI Answers Report

I am working on a BI Answers Report where the original data is sorted by unquie ID into several fields including alot of dates. Those dates where then put into for a timestampdiff count and average and seperated into a pivot table with the timestampdiff count and average columns in the measurement area with another field as a sorting in the column part of the pivot table.

The office wants to see each one of these dates so that all of them are only 45 days old or only a quarter old, etc. but sense the data is related to the unquie ID and some dates related to each ID are older than the time frame requested, but I still need access to the dates that are not older. I can't change the underlying nature of IDW unless absolutely necessary. Is there anyway to only get the dates to populate if they are past a set time through a filter so the office can change what time period they are looking at by a prompt on the dashboard.